CLASSLESS ADDRESSING

CLASSLESS ADDRESSING

•               To overcome the address depletion and give more  organizations access to the Internet,  classless addressing was designed.

•               Here there are no classes , but still addresses are granted in blocks.

•               The size  of the block (no. of addresses) varies based on the nature and size of the entity.

  RESTRICTIONS ON  CLASSLESS ADDRESS BLOCKS

1. The addresses in a block must be contiguous, one after another.

2.   The no. of addresses in a block must be a power of 2.

3.   The first address must be evenly divisible by the no.   of addresses.

Example 1

Which of the following can be the beginning  address of a block that contains 16 addresses?

205.16.37.32                  190.16.42.44

17.17.33.80                     123.45.24.52

Solution

The address 205.16.37.32 and 17.17.33.80 is eligible because the decimal value of these addresses are divisible by 16.

Example 2

Which of the following can be the beginning address of a block that contains 1024 addresses?

205.16.37.32                       190.16.42.0
17.17.32.0                            123.45.24.52

Solution

Beginning address- 17.17.32.0

Reason- Decimal value is divisible by 1024.